Fix tarball sha1sum.
Fix tarball sha1sum.

When a tarball is created for a tag, the branch-tip tarball is
not updated, but the sha1sum/md5sum commands were expecting
branch-tip tarballs.

Change-Id: I85c943ca93fae30237d458adae04c54d344c4c8f
Reviewed-on: https://review.openstack.org/19638
Reviewed-by: Clark Boylan <635fc31d01fa593720982fa0568e87170cedbe2c@gmail.com>
Reviewed-by: Jeremy Stanley <98883b97e35b7bb1ac282bb863f2e9d917db0454@yuggoth.org>
Approved: James E. Blair <e81a02a9d6405977f63a769d9f6ec8ed9d924325@inaugust.com>
Tested-by: Jenkins

open-switch/infra_puppet-jenkins,open-switch/infra_puppet-jenkins